It is possible that the main title of the report Marfan Syndrome is not the name you expected. Please check the synonyms listing to find the alternate name(s) and disorder subdivision(s) covered by this report.
As Jenny points out, being able to lisp the alphabet song at age two has little to do with 'knowing' the alphabet. And, yes, most children learn the letters by sight and sound in kindergarten, although most are capable of learning this information sooner if diligently taught by parents or others.
At what age does a child usually know their alphabet letters? Update: Don't worry everyone, my son is read to for at 45 minutes every day. You can't sit down at my house without 2yr old boy and a book suddenly appearing on your lap. He knows his alphabet too, I was just curiouse what the average age was. Thank you for all your answers.